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Published on: December 27, 2016
Quaternized chitosan derivatives inhibit growth and affect biofilm formation of Staphylococcus aureus
Alex Miranda1, Nichole D Brandquist2, Kristen Johnson3
1Department of Chemistry, University of Nebraska at Omaha, Omaha, NE, USA.
Abstract:
Antimicrobial resistance (AMR) poses a global health threat, severely impeding the effective treatment of bacterial infections and jeopardizing the safety of routine medical procedures. Methicillin-resistant Staphylococcus aureus (MRSA) is particularly problematic because of its resistance to beta-lactams and the ability to form resilient biofilms. Conventional antibiotics, including last-resort options, have serious side effects and may contribute to further resistance. Chitosan, a natural biopolymer, offers a promising alternative due to its biocompatibility and antimicrobial properties, though its effectiveness against biofilms is limited. Recent studies suggest that increasing the positive charge density and adding hydrophobic moieties to chitosan, can enhance its antimicrobial properties. In this work, the antibacterial activity of quaternized chitosan derivatives against AMR S. aureus strains was assessed. Quaternization of chitosan's amino group and introduction of hydrophobic side chains was found to significantly inhibit bacterial growth in both methicillin-sensitive (MSSA) and MRSA strains. Notably, nanofibrous materials composed of polyethylene oxide and hexyl-modified chitosan demonstrate alterations in S. aureus biofilm development, leading to significant accumulation of dead cells. Combined, these results highlight the potential of modified chitosan derivatives as effective antimicrobial agents for surface treatments and medical device coatings, particularly in applications where antibiotics are traditionally used, such as biofilm-prone environments.
Insights
Modified chitosan derivatives show potent antimicrobial activity against antibiotic-resistant bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA). These novel materials effectively inhibit bacterial growth and biofilm formation, offering a promising alternative to conventional antibiotics.
Area of Science:
- Biomaterials Science
- Microbiology
- Infectious Diseases
Background:
- Antimicrobial resistance (AMR) is a critical global health challenge, limiting treatment options for bacterial infections.
- Methicillin-resistant Staphylococcus aureus (MRSA) presents significant treatment difficulties due to its resistance to beta-lactam antibiotics and biofilm-forming capabilities.
- Conventional antibiotics have limitations, including side effects and the potential to drive further resistance.
Purpose of the Study:
- To evaluate the antibacterial efficacy of quaternized chitosan derivatives against antimicrobial-resistant Staphylococcus aureus strains.
- To investigate the impact of modified chitosan on bacterial growth and biofilm development.
- To explore the potential of these derivatives as alternatives to traditional antibiotics in medical applications.
Main Methods:
- Synthesis and characterization of quaternized chitosan derivatives with enhanced positive charge density and hydrophobic moieties.
- Assessment of antibacterial activity against methicillin-sensitive (MSSA) and MRSA strains.
- Evaluation of biofilm inhibition using nanofibrous materials composed of polyethylene oxide and hexyl-modified chitosan.
Main Results:
- Quaternized chitosan derivatives significantly inhibited the growth of both MSSA and MRSA strains.
- Nanofibrous materials incorporating hexyl-modified chitosan demonstrated significant disruption of S. aureus biofilm formation.
- These modified chitosan materials led to a substantial accumulation of dead bacterial cells within biofilms.
Conclusions:
- Modified chitosan derivatives exhibit strong potential as effective antimicrobial agents against resistant bacterial strains.
- These materials are promising for surface treatments and medical device coatings, especially in biofilm-prone environments.
- This research offers a viable alternative to conventional antibiotics for combating challenging bacterial infections.
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